In a tight spot, Any Assistance Appreciated~

So after having my HTC M8 for over a year I decided it was time to root it and flash a custom ROM because it was becoming extremely slow and unbearably sluggish. I came across quite a few guides and what not detailing steps and decided on using the Hasoon2000 "All in one Kit." Everything was going smoothly initially, I managed to unlock the bootloader, and flash a custom recovery (TWRP), but then that's when the problems started. I had an issue with updating SuperSU and it gave me an error stating that the binary was not installed and the app would not work without it. I attempted to install it via the playstore and that didn't work either. So I decided to re-flash the custom recovery and see if I couldn't reinstall the SuperSu, BUT after restarting the phone again, I got an error that kept saying that the the AT&T Ready2Go app has stopped working and it repeatedly popped up and wouldn't let me do anything at all. I tried to go into the TWRP Recovery and factory reset the phone, but this is where I royally screwed up, I went into the Advanced Wipe options and without thinking, wiped the "System" and "Cache" portion. Now not only do I have no OS, but my phone isn't event fully rooted because SuperSU was never fully working. I honestly have no idea what to do now and pretty much am without a working phone, great first attempt at rooting my phone huh?!

Also I understand getting a microsd card might facilitate fixing this issue, so probably first thing tomorrow I'll be going to get one.